The most important new result in 2017 was our (Debattista et al. 2017) demonstration that all the trends observed in the Milky Way’s bulge are produced by the evolution of the bar. Trends such as the X-shape of the metal-rich bulge stars, which is absent in the metal-poor stars, the vertical metallicity gradient, the old age of bulge stars, the weak bar of the oldest stars compared with the strong bar in slightly younger stars, and the varying kinematics of stars with metallicity, have all, in the past, been interpreted as being due to the bulge having formed partly in situ and partly accreted. Our simulations show that all these trends result purely from secular evolution of the bar itself (i.e. the bulge is part of the bar), with no hints of an accreted component other than the stellar halo, at about 1% of the Milky Way’s total stellar mass. Our results have resolved 20 years of conflicting interpretations of the origin of the Milky Way’s bulge and represent an important step in understanding it. We explained the physics of this evolution via a new concept, kinematic fractionation: the morphological separation of stellar populations on the basis of their kinematics at bar formation. The simulations predict strongly X-shaped metallicity maps in external edge-on boxy/peanut-shaped bulges, a prediction which has since been confirmed using MUSE observations (Gonzalez et al. 2017), establishing a novel link between the Milky Way and galaxies in general.